The present invention relates to a chromene derivative, a process for preparing the same and antiallergic agent containing the same as an active principle.
It was found by the present inventors that some compound showed strong antiallergic activity, the compound being present in the metabolic products obtained when administering to mammalian animals some kind of coumarin derivatives having the general formula (III): ##STR2## wherein R is alkyl group having 1 to 20 carbon atoms or alkenyl group having 2 to 20 carbon atoms and OR group is attached to 5-position, 6-position, 7-position or 8-position of the coumarin ring, which is described in Japanese Unexamined Patent Publication Nos. 76873/1980 and 71087/1981. As the result of the continuous efforts of the present inventors to obtain the compound useful for antiallergic agents, it has now been found that, among the compound having the general formula (III) wherein OR group is alkyloxy group, the compound of the general formula (III) wherein the end carbon of the corresponding alkyl side chain is carboxyl group has a strong antiallergic activity, low toxicity and high safety.